JP2012218577A - Hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress charging of a secondary battery by excessive power that can be generated when a shift position is changed from neutral.SOLUTION: When a shift position is at an N position when an output limit Wout is a value 0, a proportion difference ΔS is added to a power storage proportion SOC to set a reference power storage proportion SSOC (S130), the power storage proportion SOC is subtracted from the reference power storage proportion SSOC to set the proportion difference ΔS (S150), and input and output limits Win and Wout are corrected by a correction amount Waj which is a negative value whose absolute value becomes larger as the proportion difference ΔS is larger (S160, S170). Thus, the input and output limits Win and Wout at the N position are kept fixed, and a failure due to substantial correction of the input limit Win to the negative side, that is, the failure of charging a battery by excessive power when a shift is changed, is suppressed.

Description

  The present invention relates to a hybrid vehicle, and more particularly to a hybrid vehicle including an internal combustion engine, an electric motor capable of inputting and outputting driving power, and a secondary battery capable of exchanging electric power with the electric motor.

  Conventionally, in this type of hybrid vehicle, when the inverter that drives the motor generator is shut down due to the shift position being neutral, the state of charge of the battery estimated based on the voltage or current of the battery is When the value is smaller than a predetermined threshold value, a warning for changing the shift position to the driver has been proposed (for example, see Patent Document 1). In this hybrid vehicle, the driver changes the shift position from neutral to another shift position in accordance with the warning, thereby releasing the inverter shutdown and allowing the motor generator to charge the battery.

JP 2010-125926 A

  In a hybrid vehicle, a battery is calculated in order to calculate a storage ratio that is a ratio of the capacity of electric power that can be discharged from the battery based on the charging / discharging current and temperature of the battery, and to prevent charging and discharging of the battery due to excessive electric power. Set the output limit as the maximum power that may allow discharge from the battery based on the temperature, voltage, power storage ratio, etc. and the input limit as the maximum negative power that may allow charging the battery, The engine and the motor are controlled so as to run while performing within the range of input restriction and output restriction (hereinafter referred to as input / output restriction) in which the charging / discharging of the battery is set. Since the battery discharges spontaneously if left unattended, its output limit is determined by the battery from its capacity when the storage ratio reaches the value for the capacity required for starting the vehicle or starting the engine, plus the power that disappears to some extent due to natural discharge. The value is 0 to inhibit discharge. In this case, it may be possible to correct the input / output limit to the negative side in response to a decrease in the power storage ratio due to subsequent natural discharge so that the battery can be easily charged, but when the shift position is neutral (neutral) If the input / output limit is corrected to the negative side in response to a decrease in the storage ratio, the input / output limit is largely corrected to the negative side when the shift position is changed to the forward travel position, for example. Due to this, the battery may be charged.

  The main purpose of the hybrid vehicle of the present invention is to suppress charging of the secondary battery due to excessive electric power that can occur when the shift position is changed from neutral (neutral).

  The hybrid vehicle of the present invention employs the following means in order to achieve the main object described above.

The hybrid vehicle of the present invention
An internal combustion engine, an electric motor capable of inputting / outputting driving power, a secondary battery capable of exchanging electric power with the electric motor, and the electric power stored in the secondary battery based on the state of the secondary battery A storage ratio setting means for setting a storage ratio that is a ratio of the capacity to the total capacity, and an output as the maximum positive power that is allowed to be discharged from the secondary battery based on the state of the secondary battery and the storage ratio Input / output limit setting means for setting a limit and an input limit as a negative maximum power that is allowed to charge the secondary battery, and the secondary by the power within the range of the set output limit and input limit In a hybrid vehicle comprising drive control means for controlling the internal combustion engine and the electric motor so as to travel with charging and discharging of a battery,
When the output limit set by the input / output limit setting means is not less than or equal to 0 at every predetermined time, the power storage ratio set at that time is set as a reference power storage ratio and is set by the input / output limit setting means When the output limit is 0 or less and the shift position is not neutral, the reference power storage ratio set at that time is held, and the output limit set by the input / output limit setting means is 0 or less. Sometimes when the shift position is neutral, the ratio change amount obtained by subtracting the storage ratio set before the predetermined time from the storage ratio set at that time becomes the reference storage ratio set at that time. Reference power storage ratio setting means for setting the added value as a new reference power storage ratio;
Correction means for correcting the output limit and the input limit set by the input / output limit setting means with a negative correction value in which the absolute value increases as the ratio difference obtained by subtracting the power storage ratio from the reference power storage ratio;
It is characterized by providing.

  In the hybrid vehicle of the present invention, a power storage ratio that is a ratio of the capacity of power stored in the secondary battery to the total capacity is set based on the state of the secondary battery, and based on the state and power storage ratio of the secondary battery. Set the output limit as the maximum positive power that can be discharged from the secondary battery and the input limit as the maximum negative power that can be charged from the secondary battery, and set the output limit and input limit. The internal combustion engine and the electric motor are controlled so as to travel with charging / discharging of the secondary battery by electric power within the range. When the output limit set by the input / output limit setting means is not less than or equal to the value 0 at a predetermined time, the power storage ratio set at that time is set as the reference power storage ratio and is set by the input / output limit setting means. When the output limit is 0 or less and the shift position is not neutral, the reference charge ratio set at that time is held, and the output limit set by the input / output limit setting means is 0 or less When the shift position is neutral, the ratio change amount obtained by subtracting the storage ratio set a predetermined time from the storage ratio set at that time was added to the reference storage ratio set at that time The value is set as a new reference storage ratio, and the absolute value increases as the ratio difference obtained by subtracting the storage ratio from the reference storage ratio increases / decreases by a negative correction value. It corrects the set output restriction and input limited by limit setting means. That is, when the output limit set by the input / output limit setting means is not less than or equal to the value 0, the power storage ratio set at that time is set as the reference power storage ratio every predetermined time, and the power storage ratio is calculated from the reference power storage ratio. The output limit and the input limit set by the input / output limit setting means are corrected by a negative correction value in which the absolute value increases as the ratio difference obtained by subtraction increases, but the storage ratio is set as the reference storage ratio Therefore, the ratio difference becomes 0, and it is agreed that the output restriction and the input restriction set by the input / output restriction setting means are not corrected. If the shift position is not neutral when the output limit set by the input / output limit setting means is less than or equal to 0, the reference storage ratio set at that time is held every predetermined time, and from the reference storage ratio The output limit and the input limit set by the input / output limit setting unit are corrected by a negative correction value in which the absolute value increases as the ratio difference obtained by reducing the power storage ratio increases. In this case, since the ratio difference increases as the power storage ratio decreases due to natural discharge or the like, the output limit and the input limit set by the input / output limit setting unit are corrected by a negative correction value that increases the absolute value accordingly. . Thereby, charge of a secondary battery can be promoted. When the shift position is neutral when the output limit set by the input / output limit setting means is less than or equal to 0, the shift position is set at a predetermined time every predetermined time from the power storage ratio set at that time. The ratio change obtained by subtracting the storage ratio is set as the new reference storage ratio by adding the percentage change obtained by subtracting the storage ratio to the reference storage ratio set at that time, and the ratio difference obtained by subtracting the storage ratio from the reference storage ratio is large. The output limit and the input limit set by the input / output limit setting means are corrected by a negative correction value whose absolute value increases. The new standard power storage ratio is SOC (n), the standard power storage ratio set so far is SOC (n-1), the power storage ratio is SOC (n), and the power storage ratio before a predetermined time is SOC (n -1), and the ratio difference is ΔS (n), the new reference power storage ratio and the ratio difference can be expressed by equations (1) and (2). By substituting the right side of Expression (1) into SOC (n) on the right side of Expression (2), Expression (3) can be obtained. This equation (3) means that the ratio difference is the same as the ratio difference before a predetermined time. Accordingly, when the shift limit is neutral when the output limit set by the input / output limit setting means is 0 or less, the ratio difference is held, and thereby the output limit or input set by the input / output limit setting means is held. A correction value for correcting the restriction is also held. That is, when the shift limit is neutral when the output limit set by the input / output limit setting means is 0 or less, the corrected output limit and input limit are not corrected even if the storage ratio decreases due to natural discharge or the like. The value will be retained. As a result, when the shift position is set to a position other than neutral after that, the output limit or input limit set by the input / output limit setting means is largely corrected to the negative side, thereby charging the secondary battery with excessive power. Can be suppressed.

SSOC (n) = SSOC (n-1) + [SOC (n) -SOC (n-1)] (1)
ΔS (n) = SSOC (n) -SOC (n) (2)
ΔS (n) = SSOC (n-1) + [SOC (n) -SOC (n-1)]-SOC (n)
= SSOC (n-1) -SOC (n-1) = ΔS (n-1) (3)

  In such a hybrid vehicle of the present invention, there are three rotating elements on three axes: a generator capable of inputting and outputting power, an output shaft of the internal combustion engine, a rotating shaft of the generator, and a driving shaft connected to the axle of the vehicle. And a planetary gear mechanism connected to each other.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. 5 is a flowchart showing an example of an input / output restriction correction processing routine executed by a battery ECU 52. It is explanatory drawing which shows an example of the time change of the electrical storage ratio SOC of an Example and a comparative example, input / output restrictions Win, Wout. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 220 of a modified example. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 320 of a modified example. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 420 according to a modification.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22 that uses gasoline or light oil as fuel, an engine electronic control unit (hereinafter referred to as an engine ECU) 24 that controls the drive of the engine 22, and an engine 22. A planetary gear 30 in which a carrier is connected to the crankshaft 26 and a ring gear is connected to a drive shaft 36 connected to drive wheels 38a and 38b via a differential gear 37, and a rotor is configured as a planetary gear, for example, as a synchronous generator motor. A motor MG1 connected to 30 sun gears, a motor MG2 configured as a synchronous generator motor and having a rotor connected to the drive shaft 36, inverters 41 and 42 for driving the motors MG1 and MG2, and a motor MG1 , MG2 electronic control unit for motor (Hereinafter referred to as a motor ECU) 40, a battery 50 that exchanges electric power with the motors MG1 and MG2 via inverters 41 and 42, and a battery electronic control unit that manages the battery 50 (hereinafter referred to as a battery ECU). 52 and a hybrid electronic control unit (hereinafter referred to as HVECU) 70 for controlling the entire vehicle.

  Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. The engine ECU 24 receives signals from various sensors that detect the operating state of the engine 22, such as a crank position from a crank position sensor that detects the rotational position of the crankshaft 26 and a water temperature sensor that detects the temperature of cooling water in the engine 22. Position from the cam position sensor that detects the cooling water temperature Tw, the in-cylinder pressure Pin from the pressure sensor installed in the combustion chamber, the rotational position of the intake valve that performs intake and exhaust to the combustion chamber and the camshaft that opens and closes the exhaust valve , Throttle position SP from the throttle valve position sensor for detecting the throttle valve position, intake air amount Qa from the air flow meter attached to the intake pipe, intake air temperature Ta from the temperature sensor also attached to the intake pipe, exhaust system Attached to the sky An air-fuel ratio AF from the ratio sensor, an oxygen signal O2 from an oxygen sensor attached to the exhaust system, and the like are input via an input port, and various control signals for driving the engine 22 are input from the engine ECU 24. For example, the drive signal to the fuel injection valve, the drive signal to the throttle motor that adjusts the position of the throttle valve, the control signal to the ignition coil integrated with the igniter, the variable valve that can change the opening and closing timing of the intake valve A control signal to the timing mechanism is output via the output port. The engine ECU 24 is in communication with the HVECU 70, controls the operation of the engine 22 by a control signal from the HVECU 70, and outputs data related to the operation state of the engine 22 to the HVECU 70 as necessary. The engine ECU 24 also calculates the rotational speed of the crankshaft 26, that is, the rotational speed Ne of the engine 22 based on a signal from a crank position sensor (not shown) attached to the crankshaft 26.

  Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. The motor ECU 40 detects signals necessary for driving and controlling the motors MG1 and MG2, such as signals from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and current sensors (not shown). The phase current applied to the motors MG1 and MG2 is input via an input port, and a switching control signal for switching switching elements (not shown) of the inverters 41 and 42 is output from the motor ECU 40 to the output port. Is being output via. Further, the motor ECU 40 communicates with the hybrid electronic control unit 70, controls the driving of the motors MG1 and MG2 by the control signal from the hybrid electronic control unit 70, and relates to the operating state of the motors MG1 and MG2 as necessary. Data is output to the hybrid electronic control unit 70. The motor ECU 40 calculates the rotational speeds Nm1, Nm2 of the motors MG1, MG2 based on signals from the rotational position detection sensors 43, 44.

  The battery ECU 52 is configured as a microprocessor centered on a CPU, and includes a ROM that stores a processing program, a RAM that temporarily stores data, an input / output port, and a communication port in addition to the CPU. The battery ECU 52 is attached to a signal necessary for managing the battery 50, for example, an inter-terminal voltage from a voltage sensor (not shown) installed between the terminals of the battery 50, and a power line connected to the output terminal of the battery 50. The charging / discharging current from a current sensor (not shown), the battery temperature Tb from a temperature sensor (not shown) attached to the battery 50, and the like are input to the HVECU 70 by communication as necessary. To do. Further, the battery ECU 52 is based on the integrated value of the charge / discharge current detected by the current sensor to manage the battery 50, and the storage ratio SOC that is the ratio of the total capacity of the power that can be discharged from the battery 50 at that time. And the input / output limits Win and Wout, which are the maximum allowable power that may charge / discharge the battery 50, are calculated based on the calculated storage ratio SOC and the battery temperature Tb. The input / output limits Win and Wout of the battery 50 are set to the basic values of the input / output limits Win and Wout based on the battery temperature Tb, and the output limiting correction coefficient and the input limiting limit are set based on the storage ratio SOC of the battery 50. It can be set by setting a correction coefficient and multiplying the basic value of the set input / output limits Win and Wout by the correction coefficient.

  Although not shown, the HVECU 70 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. The HVECU 70 includes an ignition signal from the ignition switch 80, a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81, and an accelerator opening from the accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. Acc, the brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, and the like are input via the input port. As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52.

  The hybrid vehicle 20 of the embodiment thus configured calculates the required torque Tr * to be output to the drive shaft 36 based on the accelerator opening Acc and the vehicle speed V corresponding to the amount of depression of the accelerator pedal by the driver. The operation of the engine 22, the motor MG1, and the motor MG2 is controlled so that the required power corresponding to the required torque Tr * is output to the drive shaft 36. As the operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is controlled so that power corresponding to the required power is output from the engine 22, and all of the power output from the engine 22 is transmitted to the planetary gear 30 and the motor MG1. The motor MG2 converts the torque of the motor MG1 and the motor MG2 so that the motor MG1 and the motor MG2 are driven and controlled, and the power suitable for the sum of the required power and the power required for charging and discharging the battery 50 is obtained. The operation of the engine 22 is controlled so as to be output from the engine 22, and all or a part of the power output from the engine 22 with charging / discharging of the battery 50 is converted by the planetary gear 30, the motor MG1, and the motor MG2. Accordingly, the required power is output to the drive shaft 36. Charge-discharge drive mode for driving and controlling the motor MG1 and the motor MG2, there is a motor operation mode in which operation control to output a power commensurate to stop the operation of the engine 22 to the required power from the motor MG2 to the drive shaft 36. Note that the torque conversion operation mode and the charge / discharge operation mode are modes in which the engine 22 and the motors MG1, MG2 are controlled so that the required power is output to the driving force 36 with the operation of the engine 22. Since there is no difference in the control, both are hereinafter referred to as the engine operation mode.

  In the engine operation mode, the HVECU 70 sets the required torque Tr * to be output to the drive shaft 36 based on the accelerator opening Acc from the accelerator pedal position sensor 84 and the vehicle speed V from the vehicle speed sensor 88, and the set required torque Multiply Tr * by the rotational speed Nr of the drive shaft 36 (for example, the rotational speed Nm2 of the motor MG2 or the rotational speed obtained by multiplying the vehicle speed V by a conversion factor) to calculate the traveling power Pdrv required for traveling. As the power to be output from the engine 22 by subtracting the charging / discharging request power Pb * (positive value when discharging from the battery 50) obtained from the traveling power Pdrv based on the storage ratio SOC of the battery 50 The required power Pe * is set. Then, the target rotational speed Ne of the engine 22 is obtained using an operation line (for example, a fuel efficiency optimal operation line) as a relationship between the rotational speed Ne of the engine 22 and the torque Te that can efficiently output the required power Pe * from the engine 22. * And target torque Te * are set, and the motor is controlled by rotational speed feedback control so that the rotational speed Ne of the engine 22 becomes the target rotational speed Ne * within the range of the input / output limits Win and Wout of the battery 50. A torque command Tm1 * as a torque to be output from MG1 is set, and when the motor MG1 is driven by the torque command Tm1 *, the torque acting on the drive shaft 36 via the planetary gear 30 is subtracted from the required torque Tr * to reduce the motor MG2. Torque command Tm2 * and set the target rotational speed Ne * and target torque Te *. Transmitted to the engine ECU24 is Te, the torque command Tm1 *, the Tm2 * is sent to the motor ECU 40. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te *, controls the intake air amount, fuel injection control, and ignition of the engine 22 so that the engine 22 is operated by the target rotational speed Ne * and the target torque Te *. The motor ECU 40 that has received the torque commands Tm1 * and Tm2 * performs switching control of the switching elements of the inverters 41 and 42 such that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *.

  In the motor operation mode, the HVECU 70 sets a value 0 to the torque command Tm1 * of the motor MG1 and outputs the required torque Tr * to the drive shaft 36 within the range of the input / output limits Win and Wout of the battery 50. Torque command Tm2 * is set and transmitted to the motor ECU 40. Then, the motor ECU 40 that receives the torque commands Tm1 * and Tm2 * performs switching control of the switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *.

  Next, the operation of the hybrid vehicle 20 of the embodiment, particularly the operation when the power storage ratio SOC decreases and the output limit Wout reaches the value 0 will be described. FIG. 2 is a flowchart showing an example of an input / output restriction correction processing routine executed by the battery ECU 52. This routine is repeatedly executed every predetermined time (for example, every several msec, every tens of msec, every few hundred msec, etc.).

  When the input / output limit correction processing routine is executed, the battery ECU 52 first sets the input / output limits Win and Wout such as the input / output limits Win and Wout, the storage ratio SOC, the reference storage ratio SSOC, the ratio difference ΔS, and the shift position SP. A process of inputting data necessary for correction is executed (step S100). Here, the input / output limits Win and Wout are set by multiplying a basic value of the input / output limits Win and Wout set based on the battery temperature Tb by an input / output limit setting process (not shown) by a correction coefficient based on the storage rate SOC. The input is made by reading the data stored in a predetermined area of the RAM (not shown). The power storage rate SOC is input by reading a value calculated based on an integrated value of the charge / discharge current of the battery 50 by a power storage rate setting process (not shown) and stored in a predetermined area of a RAM (not shown). The reference power storage ratio SSOC is set by this routine, and is set when the routine was executed last time and stored in a predetermined area of a RAM (not shown). When the routine is executed, the input power storage ratio SOC is used as an initial value. The ratio difference ΔS is set by subtracting the power storage ratio SOC from the reference power storage ratio SSOC by this routine, and is set when the routine is executed last time and stored in a predetermined area of a RAM (not shown). The value 0 is used as the initial value when this routine is started for the first time after the system is started. The shift position SP detected by the shift position sensor 82 is input from the HVECU 70 by communication.

  When the data is thus input, it is determined whether or not the output limit Wout of the input / output limits Win and Wout that are input is less than or equal to the value 0, and whether or not the storage rate SOC is less than or equal to the reference storage rate SSOC (step S110 ) When the output limit Wout is not less than the value 0 or when the power storage rate SOC is greater than the reference power storage rate SSOC even when the output limit Wout is less than 0, the power storage rate SOC is set as the reference power storage rate SSOC (step S140). When the output limit Wout is 0 or less and the storage ratio SOC is less than or equal to the reference storage ratio SSOC, it is determined whether or not the shift position SP is a neutral position (N position) (step S120), and the shift position SP is neutral. When it is not the position (N position), the reference power storage ratio SSOC set at that time is held, and when the shift position SP is the neutral position (N position), the power storage ratio SOC added with the ratio difference ΔS is the reference power storage. The ratio SSOC is set (step S130). Here, since the ratio difference ΔS is set by executing this routine last time, in order to distinguish, the ratio difference set by this routine is set to ΔS (n) and set last time by this routine. Let that be ΔS (n−1). Similarly, regarding the reference power storage ratio SSOC, the current set or held value of this routine is set to SSOC (n), and the previously set or held value of this routine is set to SSOC (n−1). And As for the storage ratio SOC, the current input by this routine is SOC (n), and the previous input by this routine is SOC (n-1). Then, the setting of the reference power storage ratio SSOC in step S130 is as shown in the following equation (4).

  SSOC (n) = SOC (n) + ΔS (n-1) (4)

  When the reference power storage ratio SSOC (n) is set or held, the ratio difference ΔS (n) is set by the following equation (5) (step S150), and the negative value whose absolute value increases as the ratio difference ΔS increases. The correction amount Waj is set by deriving from a predetermined map (step S160), and the correction amount Waj is added to the output limit Wout and the input limit Win, respectively, as shown in equations (6) and (7). As a result, the output limit Wout and the input limit Win are corrected (step S170), and this routine ends.

ΔS (n) = SSOC (n) -SOC (n) (5)
Win ← Win + Waj (6)
Wout ← Wout + Waj ・ ・ ・ (7)

  Here, when formula (5) is substituted into ΔS (n−1) of formula (4) described above and regrouped, formula (8) is obtained. This is obtained by subtracting the storage ratio SOC (n−1) previously input by this routine from the storage ratio SOC (n) input by this routine this time, that is, the storage ratio of a predetermined time before the storage ratio SOC (n). The value obtained by subtracting SOC (n−1) is added to the reference power storage ratio SSOC (n−1) set by this routine last time. Furthermore, when the relationship of the formula (8) is applied to the reference power storage ratio SSOC (n−1) on the right side of the formula (8) until n = 1, the formula (9) and the formula (10) are obtained. This is because the reference storage ratio SSOC (n) is obtained when the shift position SP is set to the neutral position (N position) after the output limit Wout becomes 0 or the shift position SP is set to the neutral position (N position). Storage ratio input when the reference storage ratio SSOC (1) is set from the storage ratio SOC (n) input in this routine to the reference storage ratio SSOC (1) when the output limit Wout becomes 0 in the state. It means that the calculation can be performed by adding the difference obtained by subtracting SOC (1) (difference).

SSOC (n) = SOC (n) + [SSOC (n-1) -SOC (n-1)]
= SSOC (n-1) + [SOC (n) -SOC (n-1)] (8)
= SSOC (1) + Σ [SOC (n) -SOC (n-1)] (9)
= SSOC (1) + [SOC (n) -SOC (1)] (10)

  Further, when the formula (4) is substituted into the reference power storage ratio SSOC (n) of the first term on the right side of the formula (5), the following formula (11) is obtained. This is because when the output limit Wout is 0 and the shift position SP is in the neutral position (N position), the ratio difference ΔS (n) does not change, that is, the reference storage ratio SSOC (n) and the storage ratio SOC ( This means that the difference from n) does not change.

ΔS (n) = SSOC (n) -SOC (n)
= [SOC (n) + ΔS (n-1)]-SOC (n)
= ΔS (n-1) (11)

  FIG. 3 shows an example of how the shift position SP, power storage ratio SOC, reference power storage ratio SSOC, input / output limit Win, Wout change over time in the two cases (Case A and Case B) of the embodiment and the comparative example. It is explanatory drawing. In case A, when the shift position SP is in the neutral position (N position), the power storage ratio SOC is reduced and the output limit Wout becomes 0. Thereafter, the shift position SP is a position other than the neutral position (for example, a forward travel position). Case B is a case where the shift position SP is in a position other than the neutral position, and the storage rate SOC is reduced and the output limit Wout becomes 0, and then the shift position SP is changed to the parking position SP. This is a case where the neutral position is set and the position is changed to a position other than the neutral position. Further, the comparative example is a process of setting the storage ratio SOC when the output limit Wout becomes the value 0 to the reference storage ratio SSOC and holding the reference storage ratio SSOC until the output limit Wout becomes greater than the value 0, that is, This is a case where the processing excluding steps S120 and S130 is executed in the input / output restriction correction processing routine of FIG.

  In the comparative example, the output limit Wout becomes the value 0 at the time T1 when the storage rate SOC reaches the predetermined threshold value Sref in order to set the output limit Wout to the value 0, and the reference storage rate SOCC (1) includes the storage rate SOC. (1) That is, the threshold value Sref is set. Thereafter, until the time T3 when the shift position SP is changed to a position other than the neutral position, the power storage ratio SOC (n) decreases due to natural discharge or the like as time elapses. Since the threshold Sref set at time T1 is held for the reference storage ratio SSOC (n), the ratio difference ΔS (n) is a negative value whose absolute value increases as the storage ratio SOC (n) decreases. Is set, and the correction value Waj is also set to a negative value whose absolute value increases as the power storage rate SOC (n) decreases. For this reason, the input / output limits Win and Wout are also corrected so as to increase toward the negative side as the storage ratio SOC decreases. The reference power storage rate SSOC of the comparative example and the input / output limits Win and Wout before correction are shown as one-dot chain lines in the power storage rate SOC and the input / output limits Win and Wout of the comparative example of FIG. Therefore, when the battery 50 is charged immediately after the time T3 when the shift position SP is changed to a position other than the neutral position, the charging power of the battery 50 is limited by the input limit Win set at the time T3. Therefore, the charging power is larger than the original input limit Win (input limit Win not subjected to the correction in step S170).

  In case A, the output limit Wout becomes 0 at time T1 when the power storage rate SOC reaches the threshold value Sref, and the power storage rate SOC (1), that is, the threshold value Sref is set as the reference power storage rate SSOC (1). Thereafter, until the time T3 when the shift position SP is changed to a position other than the neutral position, the power storage ratio SOC (n) decreases due to natural discharge or the like as time elapses. Since the shift position SP is the neutral position, the reference power storage ratio SSOC (n) is set by the above-described equation (4) at step S130. However, as described above, the equation (4) is rewritten to the equation (10). Therefore, by substituting the storage ratio SOC (1) for the reference storage ratio SOCOC (1) in the first term on the right side of the equation (10), the reference storage ratio SOCOC (n) matches the storage ratio SOC (n). I understand. For this reason, the ratio difference ΔS (n) set in step S150 becomes 0 according to equation (5), and the value 0 is set for the correction amount Waj in step S160. Therefore, the input / output limits Win and Wout are set in step S170. Correction is performed with a correction amount Waj of 0. That is, the input / output restrictions Win and Wout are not corrected at all. Therefore, as indicated by the input / output limits Win and Wout of case A in FIG. 3, the output limit Wout holds the value 0 and the input limit Win also holds the same value from time T1 to time T3. Therefore, when the battery 50 is charged immediately after the time T3 when the shift position SP is changed to a position other than the neutral position, the charging power of the battery 50 is limited by the input limit Win, so that the charging power becomes excessive. There is nothing.

  In case B, the output limit Wout becomes 0 at time T1 when the power storage rate SOC reaches the threshold value Sref, and the power storage rate SOC (1), that is, the threshold value Sref is set as the reference power storage rate SSOC (1). Thereafter, until the time T2 when the shift position SP is changed to the neutral position is reached, the power storage rate SOC (n) decreases with time due to natural discharge or the like. Since the reference power storage ratio SSOC (n) is a position other than the neutral position, the reference power storage ratio SSOC (1) set at time T1, that is, the threshold value Sref is held. The reference power storage ratio SSOC of case B is shown as a one-dot chain line in the power storage ratio SOC of case B in FIG. From time T1 to time T2, the power storage ratio SOC (n) decreases with time, and the reference power storage ratio SSOC (n) holds the threshold value Sref. Therefore, the ratio difference ΔS (n) is expressed by the formula ( 5) sets a negative value whose absolute value increases with time. Accordingly, a negative value whose absolute value increases with the passage of time is also set as the correction amount Waj, and the input / output limits Win and Wout are corrected so as to increase toward the negative side with the passage of time. The input / output limits Win and Wout before correction of case B are shown as a one-dot chain line in the input / output limits Win and Wout of case B in FIG. When the shift position SP is changed from a position other than the neutral position to the neutral position at time T2, the storage rate SOC (n) has elapsed until time T3 when the shift position SP is changed to a position other than the neutral position. Along with this, it becomes smaller due to spontaneous discharge. Since the shift position SP is the neutral position, the difference (ratio difference ΔS (n)) from the storage ratio SOC (n) is held as the reference storage ratio SSOC (n) as shown in the above-described equation (11). . Therefore, since the correction amount Waj holds the value set at time T2, the input / output limits Win and Wout corrected by the correction amount Waj also hold the value set at time T2. Therefore, when the battery 50 is charged immediately after the time T3 when the shift position SP is changed to a position other than the neutral position, the charging power of the battery 50 is limited by the input limit Win set at the time T2. Thus, the charging power is slightly larger than the original input limit Win (input limit Win not subjected to the correction in step S170), but is not excessive.

  According to the hybrid vehicle 20 of the embodiment described above, when the power storage rate SOC decreases and the output limit Wout reaches the value 0, when the shift position SP is the neutral position (N position), the power storage rate SOC ( n) plus the ratio difference ΔS (n−1) is set as the reference power storage ratio SSOC (n), and the power storage ratio SOC (n) is subtracted from the set reference power storage ratio SSOC (n) to obtain the ratio difference ΔS ( n) is set, the correction amount Waj is set as a negative value whose absolute value increases as the set ratio difference ΔS increases, and the output limit Wout is added to the output limit Wout and the input limit Win, respectively. And, in other words, by subtracting the storage ratio SOC (n−1) of a predetermined time from the storage ratio SOC (n). Is set as the reference power storage ratio SSOC (n) in addition to the reference power storage ratio SSOC (n-1) previously set by this routine, and the power storage ratio SOC (n) is subtracted from the set reference power storage ratio SSOC (n). The ratio difference ΔS (n) is set, the correction amount Waj is set as a negative value whose absolute value increases as the set ratio difference ΔS increases, and the correction amount Waj is added to the output limit Wout and the input limit Win, respectively. Thus, by correcting the output limit Wout and the input limit Win, the ratio difference ΔS when the shift position SP is the N position can be kept constant. As a result, as the ratio difference ΔS increases as a negative value, an inconvenience caused by the correction of the output limit Wout and the input limit Win greatly on the negative side, that is, the shift position SP is changed to a position other than the neutral position. In this case, it is possible to suppress the inconvenience that the battery 50 is charged by excessive electric power. Of course, when the storage rate SOC decreases and the output limit Wout reaches the value 0, when the shift position SP is a position other than the neutral position, the storage rate SOC decreases and the output limit Wout reaches the value 0. Is stored as the reference storage ratio SSOC (n), and the storage ratio SOC (n) is subtracted from the stored reference storage ratio SSOC (n) to set the ratio difference ΔS (n). The correction amount Waj is set as a negative value whose absolute value increases as the ratio difference ΔS increases, and the output limit Wout and the input limit Win are corrected by adding the correction amount Waj to the output limit Wout and the input limit Win, respectively. By doing so, it is possible to correct the output limit Wout and the input limit Win so that the battery 50 is easily charged. As a result, the battery 50 can be charged quickly.

  In the hybrid vehicle 20 of the embodiment, the power of the motor MG2 is output to the drive shaft 36. However, as illustrated in the hybrid vehicle 120 of the modification of FIG. 4, the drive shaft 36 is connected to the power of the motor MG2. It may be connected to an axle (an axle connected to the wheels 39a and 39b in FIG. 4) different from the other axle (the axle to which the drive wheels 38a and 38b are connected).

  In the hybrid vehicle 20 of the embodiment, the power of the engine 22 is output to the drive shaft 36 connected to the drive wheels 38a and 38b via the planetary gear 30, but this is exemplified in the hybrid vehicle 220 of the modification of FIG. As described above, the inner rotor 232 connected to the crankshaft of the engine 22 and the outer rotor 234 connected to the drive shaft 36 that outputs power to the drive wheels 38a and 38b are driven, and a part of the power of the engine 22 is driven. A counter-rotor motor 230 that transmits power to the shaft 36 and converts remaining power into electric power may be provided.

  In the hybrid vehicle 20 of the embodiment, the power from the engine 22 is output to the drive shaft 36 connected to the drive wheels 38a and 38b via the planetary gear 30, and the power from the motor MG2 is output to the drive shaft 36. However, as illustrated in the hybrid vehicle 320 of the modification of FIG. 6, a motor MG is attached to the drive shaft 36 connected to the drive wheels 38 a and 38 b via the transmission 330, and a clutch 329 is attached to the rotation shaft of the motor MG. The power from the engine 22 is output to the drive shaft 36 via the rotation shaft of the motor MG and the transmission 330, and the power from the motor MG is output to the drive shaft via the transmission 330. It is good also as what outputs to. Alternatively, as illustrated in the hybrid vehicle 420 of the modified example of FIG. 7, the power from the engine 22 is output to the drive shaft 36 connected to the drive wheels 38 a and 38 b via the transmission 430 and the power from the motor MG. May be output to an axle different from the axle to which the drive wheels 38a, 38b are connected (the axle connected to the wheels 39a, 39b in FIG. 7). In other words, any type of hybrid vehicle may be used as long as it includes an engine and an electric motor that outputs driving power.

  In the embodiments, the present invention has been described as the form of the hybrid vehicle 20, but may be a form of a vehicle other than the automobile or a form of a vehicle control method.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the engine 22 corresponds to an “internal combustion engine”, the motor MG2 corresponds to an “electric motor”, the battery 50 corresponds to a “secondary battery”, and charging / discharging of the battery 50 detected by a current sensor (not shown). The battery ECU 52 that calculates the storage ratio SOC, which is the ratio of the total capacity of the power that can be discharged from the battery 50 at that time, based on the integrated value of the current corresponds to the “storage ratio setting means” and is based on the battery temperature Tb. The basic values of the input / output limits Win and Wout are set, the output limiting correction coefficient and the input limiting correction coefficient are set based on the storage ratio SOC of the battery 50, and the set basic values of the input / output limits Win and Wout are set. The battery ECU 52 for setting the input / output limits Win and Wout by multiplying the correction coefficient by the correction coefficient corresponds to the “input / output limit setting means”, and the accelerator opening The required torque Tr * is set based on the cc and the vehicle speed V, the travel power Pdrv is calculated based on the required torque Tr *, and the charge / discharge required power Pb * based on the storage ratio SOC of the battery 50 is calculated from the travel power Pdrv. Is set to the required power Pe * to be output from the engine 22, the target rotational speed Ne * and the target torque Te * of the engine 22 are set from the required power Pe * and the operation line, and the input / output limit of the battery 50 is set. Within the range of Win and Wout, the torque command Tm1 * of the motor MG1 is set so that the rotational speed Ne of the engine 22 becomes the target rotational speed Ne *, and the motor MG1 is driven by the torque command Tm1 * via the planetary gear 30. Then, the torque command Tm2 * of the motor MG2 is set by subtracting the torque acting on the drive shaft 36 from the required torque Tr *. The target rotational speed Ne * and the target torque Te * are transmitted to the engine ECU 24, the torque commands Tm1 * and Tm2 * are transmitted to the motor ECU 40, and the received target rotational speed Ne * and the target torque Te * An engine ECU 24 that performs intake air amount control, fuel injection control, ignition control, etc. of the engine 22 so that the engine 22 is operated, and an inverter 41, so that the motors MG1, MG2 are driven by the received torque commands Tm1 *, Tm2 *. The motor ECU 40 that performs switching control of the switching elements 42 corresponds to “drive control means”, and the battery ECU 52 that executes the processing from step S100 to S140 of the input / output restriction correction processing routine of FIG. Corresponding to “setting means” and the input / output restriction correction processing of FIG. The battery ECU 52 that executes the processing of steps S150 to S170 of the routine corresponds to “correction means”.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the manufacturing industry of hybrid vehicles.

  20, 120, 220, 320, 420 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 30 planetary gear, 36 drive shaft, 37 differential gear, 38a, 38b drive wheel, 39a, 39b wheel, 40 motor Electronic control unit (motor ECU), 41, 42 inverter, 43, 44 rotational position detection sensor, 50 battery, 52 electronic control unit for battery (battery ECU), 70 electronic control unit for hybrid (HVECU), 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor, 2 0 the pair-rotor motor, 232 an inner rotor, 234 outer rotor, 329 clutches, 330 and 430 transmission, MG, MG1, MG2 motor.

Claims (1)

An internal combustion engine, an electric motor capable of inputting / outputting driving power, a secondary battery capable of exchanging electric power with the electric motor, and the electric power stored in the secondary battery based on the state of the secondary battery A storage ratio setting means for setting a storage ratio that is a ratio of the capacity to the total capacity, and an output as the maximum positive power that is allowed to be discharged from the secondary battery based on the state of the secondary battery and the storage ratio Input / output limit setting means for setting a limit and an input limit as a negative maximum power that is allowed to charge the secondary battery, and the secondary by the power within the range of the set output limit and input limit In a hybrid vehicle comprising drive control means for controlling the internal combustion engine and the electric motor so as to travel with charging and discharging of a battery,
When the output limit set by the input / output limit setting means is not less than or equal to 0 at every predetermined time, the power storage ratio set at that time is set as a reference power storage ratio and is set by the input / output limit setting means When the output limit is 0 or less and the shift position is not neutral, the reference power storage ratio set at that time is held, and the output limit set by the input / output limit setting means is 0 or less. Sometimes when the shift position is neutral, the ratio change amount obtained by subtracting the storage ratio set before the predetermined time from the storage ratio set at that time becomes the reference storage ratio set at that time. Reference power storage ratio setting means for setting the added value as a new reference power storage ratio;
Correction means for correcting the output limit and the input limit set by the input / output limit setting means with a negative correction value in which the absolute value increases as the ratio difference obtained by subtracting the power storage ratio from the reference power storage ratio;
A hybrid vehicle comprising:

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